The SLAC Beam Physics group and other SLAC collaborators continue to study options for implementing a near diffraction-limited ring-based light source in the 2.2-km PEP-II tunnel that will serve the SSRL scientific program in the future. The study team has completed the baseline design for a 4.5-GeV storage ring having 160 pm-rad emittance with stored beam current of 1.5 A, providing > 10^22 brightness for multi-keV photon beams from 3.5-m undulator sources. The team has also investigated possible 5-GeV ERL configurations which, similar to the Cornell and KEK ERL plans, would have ~30 pm-rad emittance with 100 mA current, and ~10 pm-rad emittance with 25 mA or less. Now a 4.5-GeV "ultimate" storage ring having emittance similar to the ERL and operating with ~200 mA is under study. An overview of the progress of the PEP-X design study and SSRLs plans for defining performance parameters that will guide the choice of ring options is presented. Show Partial Abstract